You can't claim a spouse as your dependent on your taxes. Are there any other tax benefits available?

You and your spouse can file as a couple (married filing joint) MFJ and you get the exemption and standard deduction of a couple.

In reality, you are correct. You can't claim your own spouse as a dependent. What you do if file a joint return with your spouse even if only one had income - perfectly legal. That is effectively counting her as a dependent but as a different type of dependent. You can't file a joint return, then still claim your spouse as a dependent - the SSANs will appear twice which is a big red flag. The spouse's SSAN appears at the top of the form. If you also include your spouse as a dependent, you have to enter their SSAN on the line where you list your dependents. That would be a double deduction.

True. But they can file a joint return, which is for most an even better deal - they get a second exemption, a second standard deduction, and lower tax rates. If one of them filed as single and claimed the other as a dependent, they COST themselves money.

When you file "married filing jointly" you get the same deductions as claiming a spouse as a dependent.

There are idiots who prepare tax returns, no doubt about that. They would pay less tax by filing a joint return, and can file a joint return even if only one had income.

They claim each other by simply choosing to file a joint return. It is kinda automatic and built-in.